The present invention relates to a method of manufacturing eyeglass frames having a front piece comprising a pair of lens-bearing rims, and, on the outermost side of each of them, a nose for the hingeing of a temple piece, which noses are integral with the corresponding lens rim.
The most critical point in eyeglass frames, and in particular in flexible eyeglass frames, consists of the connection between the front piece of the frame and the temple pieces. This connection is effected at a place commonly known in the industry as a "nose".
In most cases, the noses are connected to the outermost parts of the respective lens-bearing rims of the eyeglass frame by welding, brazing or similar procedures involving the action of heat on the lens rim.
This results in a local weakening of the lens rim and therefore in the possibility of permanent deformations or breaks thereof in one of its most stressed zones, namely at the place of attachment of the nose.
Some known solutions directed at obviating these drawbacks consist of noses which can be fitted by mortising or clamping to the lens-bearing rims.
For this purpose, the known method proposed for the manufacture of an eyeglass frame contemplates separate production of the lens rims and the parts integral with them and a subsequent phase of attachment of the noses produced with separate machines and on separate lines.
This solution, although obviating the drawback of weakening of the rim in the region of attachment of the nose, has numerous drawbacks, including primarily the fact that, in view of the small size of the nose and the necessity of accurate connections, the production of the nose and of the corresponding rim is subject to very close tolerances; furthermore, as there is concerned a part which is separate from the lens rim and subsequently fastened to it, problems of loss of rigidity in the nose-rim connection can arise in time, with a consequent loss of the effectiveness of the eyeglass frame.
The necessity of producing the noses separately from the remaining parts of the front piece substantially impairs the economy of the production of the frames, both because of the aformentioned different lines of production and machines and because of the need of an additional step of assembling the noses to the lens rims.
The technical problem forming the basis of the present invention is to create a method of manufacturing front pieces for eyeglass frames which overcomes the above-mentioned drawbacks of the prior art.